基于色素蛋白复合体的DSSC的新型宽光谱高效染料的筛选与合成

There is considerable interest by making full use of solar energy via photosynthesis to create alternative forms of fuel or new energy. Pigment protein complex is not only an important unit for convertion and usage of solar energy via photosynthesis, but also a potential crucial constructive element for photoinduced current generator in dye-sensitized solar cells in vitro. At present, it is regareded potentially as a clean, renewable and sustainable source of fuel, the quantity of the study on production of electricity by pigment protein complex is increasing, but several challenges exist..Pigment?protein complexes isolated from anoxygenic phototrophic bacteria are capable of reflecting to broad spectrum of solar energy from 300nm to 1000nm wavelength. However, lower photocurrent conversion effiency of pigment-preteion complex used for dye-sensitived slar energy cell is observed.What are the reasons for lower photocurrent conversion ? Is the reason casued by the difference in composition and structure of pigment-protein complex,or by electron generated by excition of pigment-proteion compleses failure to introduce into TiO2 semiconductor region? On the basis of the studies for purification, dissociation and reconstitution of pigment-proteion complex, we attempts to develop photocurrent conversion systems by immobilized a self-repaired of the LH complexes or RC complexesnto electrodes with a TiO2 nanostructured film to extend for the development of a dye-sensitized biosolar cell system.Firstly, pigment proteion complexes are to be isolated from six species of purple bacteria, and then synthesize novel pigment proteion complexes with different structure and composition properties by modification, dissocaition and reconstruction techniques. To promote electron incorporation efficiency from excited pigment-protein complex into TiO2 film, pigment-protein complexes are immobilized directly onto electrode with a TiO2 nanostructured film or immobilized indrectly onto electrode with nanostructured TiO2 film by incorporating carbon nanotubes, gold nanoparticles into membrane lipid. By optimizing and controling environmental parameter, sensitizers with wide-spectra absorption properties for high performance dye-sensitized solar cells will be obtained. The aim of this project to gain insight into the photocurrent activity of the pigment proteion complex, and shed light on novel function of pigment?protein complexes.

利用色素蛋白复合体（PPC）进行光电转化已成为新的能源研究热点，不产氧光合细菌APB的PPC具有能利用太阳能全光谱的突出优势，但用于敏化太阳能电池（DSSC）光电转化效率较低，这是由选用的PPC结构与组成差异所引起？还是PPC光激发的电子不能快速有效导入半导体材料？本课题拟在PPC纯化、拆分与组装研究基础上，以光电转化效率为主要指标，系统比较源自不同吸光特性的6种紫细菌的纯化PPC，并通过拆分、衍生与修饰、组装等手段，合成结构组成和性能不同的新型PPC，将这些新型PPC直接固定于TiO2薄膜或与膜脂、碳纳米管和金纳米粒子组装成有机高密度阵列的PPC固定于TiO2薄膜，以提高电子导入TiO2导带的能力，再通过优化环境因素获得高效染料元件，构建出宽光谱、稳定性强的高效DSSC。这将为DSSC中新型光敏元件关键技术突破提供很有价值的参考数据和思路，也必将为光合作用机理的深入阐明提供新见解。

基于自然界光合作用机理的DSSC研究备受关注，基于不产氧光合细菌光合元件的DSSC已成为新的能源研究热点，不产氧光合细菌光合元件具有能利用太阳能全光谱的明显优势，本文从3种典型紫细菌中获得了7种具有不同吸光范围、极性和结构的细菌叶绿素和类胡萝卜素以及3种改性BChl 。在此基础上，较系统的比较了天然与改性BChl 、多组分与单一组分Car、色素浓度、BChl a和Car共敏对DSSC光电性能的影响，并对色素与半导体材料的相互作用进行了表征，结果显示在不添加任何分散剂的条件下，具有近红外吸收的天然BChl 光电转化性能较优。单一组分Car比多组分Car具有较高的光电性能，玫红品Car光电转换效率最佳。BChl a敏化TiO2薄膜电极，吸收光谱红移，800 nm特征荧光淬灭。BChl a与Car共敏TiO2薄膜电极，拓宽了可见光吸收光谱，短路电流和光电转换效率提高了12%和7.3%。用TiCl4和HAc处理TiO2薄膜后，可明显提高BChl a的光电转换效率。在此基础上，我们通过调控环境参数，分离纯化获得了具有多种不同光谱特性的色素蛋白复合体，通过拆分组装以及DSSC条件优化，获得了性能不同的DSSC高效敏化染料元件，构建出了宽光谱稳定性好的高效DSSC，基于LH2的DSSC的最大Isc和光电转化效率是迄今报道结果的两倍，基于RC的DSSC的最大的转换效率是迄今报道结果的3倍，且光电流响应能维持稳定。进一步研究揭示构建CNTs参与介导的自组装DSSC体系可有效提高天然捕光色素蛋白复合体在太阳能电池中的光电转换效率。